Test IK evaluation bug

.travis.yml

@@ -43,4 +43,4 @@ script:
     -v $(pwd):/repo
     --workdir=/repo
     --entrypoint mayapy
-    mottosso/maya:${VERSION} run.py
+    mottosso/maya:${VERSION} -m nose.__main__ --verbose run.py

run.py

@@ -1,6 +1,106 @@
+from nose.tools import with_setup, assert_equals, assert_not_equals
 from maya import standalone, cmds
-standalone.initialize()
 
-cmds.file(new=True, force=True)
-cube, _ = cmds.polyCube(name="testCube")
-print(cube)
+a = "Root"
+b = "Mid"
+c = "Tip"
+
+
+def setup():
+    """Called automatically on start-up"""
+    standalone.initialize()
+
+
+def new():
+    # Build Scene
+    # o     o
+    #  \   /
+    #   \ /
+    #    o
+    #
+    cmds.file(new=True, force=True)
+    cmds.joint(name=a, position=(0, 0, 20))
+    cmds.joint(name=b, position=(0, 0, 0), relative=False)
+    cmds.joint(name=c, position=(0, 10, -20), relative=False)
+    handle, eff = cmds.ikHandle(
+        solver="ikRPsolver",
+        startJoint=a,
+        endEffector=c,
+    )
+
+
+@with_setup(new)
+def test_bug():
+    """Test bug
+
+    Ensure that the bug occurs
+
+    """
+
+    assert_equals(cmds.getAttr(a + ".rx"), 0.0)
+    assert_equals(cmds.getAttr(a + ".rx", time=1), 0.0)
+
+    # Move handle
+    cmds.move(0, 15, -10, "|ikHandle1")
+
+    assert_equals(round(cmds.getAttr(a + ".rx"), 0), -14.0)
+
+    # This is the bug
+    assert_not_equals(round(cmds.getAttr(a + ".rx", time=1), 0), -14.0)
+
+
+@with_setup(new)
+def test_workaround():
+    """Test workaround
+
+    Workaround the issue by querying each attribute twice
+
+    """
+
+    def getAttr(attr, time):
+        cmds.getAttr(attr, time=time - 1)
+        return cmds.getAttr(attr, time=time)
+
+    assert_equals(cmds.getAttr(a + ".rx"), 0.0)
+    assert_equals(cmds.getAttr(a + ".rx", time=1), 0.0)
+
+    # Move handle
+    cmds.move(0, 15, -10, "|ikHandle1")
+
+    assert_equals(round(cmds.getAttr(a + ".rx"), 0), -14.0)
+    assert_equals(round(getAttr(a + ".rx", time=1), 0), -14.0)
+
+
+@with_setup(new)
+def test_optimisation():
+    """Test optimisation
+
+    If the cause of the bug is ikHandle, then once an attribute has
+    been called twice and triggered the evaluation of ikHandle, the
+    next dependent node can be called just once.
+
+    """
+
+    def getAttr(attr, time):
+        cmds.getAttr(attr, time=time - 1)
+        return cmds.getAttr(attr, time=time)
+
+    assert_equals(cmds.getAttr(a + ".rx"), 0.0)
+    assert_equals(cmds.getAttr(a + ".rx", time=1), 0.0)
+
+    # Move handle
+    cmds.move(0, 15, -10, "|ikHandle1")
+
+    assert_equals(round(cmds.getAttr(a + ".rx"), 0), -14.0)
+    assert_equals(round(getAttr(a + ".rx", time=1), 0), -14.0)
+
+    # The above call also enables this other node to evaluate properly
+    # Which means we only need to call the special function once
+    # per IK node.
+    assert_equals(round(cmds.getAttr(b + ".rx", time=1), 0), 49.0)
+
+    cmds.move(0, 15, -15, "|ikHandle1")
+
+    # Once out-of-date again, the workaround must be applied
+    assert_not_equals(round(cmds.getAttr(a + ".rx", time=1), 0), -4.0)
+    assert_equals(round(getAttr(a + ".rx", time=1), 0), -4.0)